Abstract
The central dogma of molecular biology rests on two kinds of asymmetry between genomes and enzymes1. Information flows from genomes to enzymes, but not from enzymes to genomes: informatic asymmetry. Enzymes provide catalysis, whereas genomes do not: catalytic asymmetry. How did these asymmetries originate? Here we demonstrate that these asymmetries can spontaneously arise from conflict between selection at the molecular level and selection Extended Data Figures and Supplementaryat the cellular level. Our model consists of a population of protocells, each containing a population of replicating catalytic molecules. The molecules are assumed to face a trade-off between serving as catalysts and serving as templates. This trade-off causes conflicting multi-level selection: serving as catalysts is favoured by cellular-level selection, whereas serving as templates is favoured by molecular-level selection. This conflict induces informatic and catalytic symmetry breaking, whereby the molecules differentiate into genomes and enzymes, hence establishing the central dogma. We show mathematically that the symmetry breaking is caused by positive feedback between Fisher’s reproductive values and the relative impact of selection at different levels. Our work proposes that the central dogma is a logical consequence of conflicting multi-level selection, hence making it no longer a ‘dogma.’
Footnotes
↵* nobuto.takeuchi{at}auckland.ac.nz